North Hempstead's noise ordinance offers promise that residents can expect to enjoy quiet neighborhoods:" . . . unreasonably loud, disturbing or unusual noises affect and are a detriment to the peace, welfare, safety, convenience and health of the residents of the Town, and it is the policy of the Town to prevent such noises."

But those words haven't offered much peace in one section of Manhasset. In an email, resident Brian Byer told us: "I am woken daily by 4:30 a.m. by noise."

He identified the primary source as an exhaust fan on the roof of a nearby bagel shop on Plandome Road.

The shop, along with seven others, backs onto Byer's neighborhood. The closest residents live in apartment buildings, and many have a view of the businesses' rear entries. The proximity is apparent, so anyone moving in can expect to hear sounds associated with daily comings and goings at those establishments -- one is a gas station, another a bar.

What they wouldn't anticipate is noise in the middle of the night, when the exhaust fan goes to work. Bagels are baked on the premises and are hot from the oven when the doors open to customers as early as 5:30 a.m.

Byer presumes the exhaust fan isn't quiet because it's worn out. He has been pressing for its repair or replacement.

Town code specifically prohibits the operation of commercial equipment that creates a noise disturbance "across a residential real property boundary" from 10 p.m. to 8 a.m. One of the 10 factors to be considered in determining if a noise constitutes a violation is this: "proximity of the sound to residential sleeping facilities."

Many bedroom windows, Byer's among them, face the back of the bagel shop.

So we were puzzled why the noise ordinance hadn't come into play.

An initial explanation came from town spokesman Collin Nash, who said that on two visits to the site last year, both times at 6 a.m., code enforcement staff determined that the fan noise was not loud enough to qualify as a violation of town code. The town did take action on other activities that contributed to the noise level, issuing violations for loading and unloading trucks at that hour.

"We have gone over there and listened on several occasions when we have had complaints," Nash said. "And the noise, according to our code enforcement people, did not appear to be intrusive. It's not intrusive to the point where it would keep somebody awake."

Byer would contest that.

The town and neighbors agree that noise from the fan is less intrusive during daylight when it's surrounded by other sounds, most involving traffic. When we visited late one morning, the fan's hum was constant, serving as background to traffic noise. As such, it wasn't particularly obtrusive.

But when the fan is switched on hours before daylight, it intrudes into an otherwise silent night.

"In the middle of the day, the town is awake, cars are going by," Byer said. "But in the middle of night . . . what's no big deal in the middle of the day at night is a problem."

Earlier this month, the town took a step to try to turn down the volume.

On Feb. 5, Nash called us to report that Supervisor Jon Kaiman and Councilwoman Anna Kaplan had paid their own visit to the bagel shop -- they arrived at midday -- to listen to the noise and talk with the owner. They left with the understanding that he plans to have work done to reduce the fan's noise level.

But first, he will need a permit from the town.

"He is waiting for a permit from us to change the motor and relocate the unit on the roof," Nash said. "Obviously, we'll work to make sure he gets those pronto so he can do what he needs to do."

Watchdog called the shop, Manhasset Bagels, and spoke to owner Randy Malka. He declined to discuss the noise or his plans to correct it.

"I'm working with the town on this. There's nothing I can say," Malka said.

Byer's complaints to the town have produced other results: Pre-dawn deliveries and garbage collection, which he said had started as early as 2:30 a.m., are arriving later. The delivery trucks, which had been backing up to the shop's back door with reverse-signal beeps, are parking on the street and drivers are using hand carts to wheel provisions into the shop.